DIR for Travel and Deco bottles?

[beanojones]

There is no such thing as "travel mix". There are the deco gasses and if needed stage cylinders of bottom gas. Travel mix is something made up by people who don't know better.

Can you explain what you mean by that?

 

[rainman_02]

MoCal DIR - Watch Video

AL80 is a stage of bottom mix (21/35 in the backgas and the AL80). AL40 is a bottle of 50%. You just simply follow the DIR procedure for verifying your gas before you ever switch. If you always check your bottles the same way and follow every step in order whether you're carrying one or three bottles, you won't mess it up...but if you do, your teammate(s) are watching to double check you.

When team leader signals switch:

1) Check depth gauge
2) Grab bottle by valve knob, verify MOD/correct gas
3) Trace reg hose down to reg and pull it out
4) Trace hose back to 1st stage to verify you have the same reg and valve; pressurize reg and turn off valve
5) Purge reg, verify correct gauge by watching needle decrease
6) Turn on valve fully, loop 40" hose over neck
7) Verify depth on depth gauge, switch regs, clip off long hose
8) Show MOD to teammate(s) and get an OK back

 

[Rick Inman]

Can you explain what you mean by that?

May I ask you first, under what circumstances do you feel you would need a "travel" gas bottle?

 

[Cheekymonkey]

May I ask you first, under what circumstances do you feel you would need a "travel" gas bottle?

I can't know for sure what he is thinking, but the first thing that comes to mind for me is say a 16% O2 bottom gas, then perhaps he is thinking of a travel gas down to depth without depleting any deco gas.
But thats just the first thing that popped into my head.

 

[beanojones]

May I ask you first, under what circumstances do you feel you would need a "travel" gas bottle?

Hypoxic bottom mix?

 

[rjack321]

Hypoxic bottom mix?

Define hypoxic.

The leanest gas most people ever use is 15/55 and you can just switch to that and drop. Rarely is anyone using 10/70, the next standard gas. But assuming you are doing some 300ft+ dive on 10/70. If so you have multiple deco gases. Probably O2, 50%, 35/25 and possibly 21/35. Just breath 21/35 or really any of those deco gases until 20ft and then go to your backgas. Done.

There's no such thing as "travel gas" in DIR terminology. If you "need" a "travel gas", you apparently aren't looking at what you have to carry already for deco.

 

[beanojones]

Define hypoxic.

The leanest gas most people ever use is 15/55 and you can just switch to that and drop. Rarely is anyone using 10/70, the next standard gas. But assuming you are doing some 300ft+ dive on 10/70. If so you have multiple deco gases. Probably O2, 50%, 35/25 and possibly 21/35. Just breath 21/35 or really any of those deco gases until 20ft and then go to your backgas. Done.

There's no such thing as "travel gas" in DIR terminology. If you "need" a "travel gas", you apparently aren't looking at what you have to carry already for deco.

??

We seem to be are hanging up on the word 'travel'. It's the 110 foot through 40 foot deco gas, or the travel gas. It's the same thing.

Is it the DIR standard really to breathe a hypoxic mix at the surface?

 

[Rick Inman]

15/55 is .16 at 05'.

 

[Bismark]

??

We seem to be are hanging up on the word 'travel'. It's the 110 foot through 40 foot deco gas, or the travel gas. It's the same thing.

Is it the DIR standard really to breathe a hypoxic mix at the surface?

I am not sure what you mean by the first part of your statement. DIR does not have a "110' through 40' deco gas".

We breath air at the surface, just like anyone else

 

[JeffG]

15/55 is .16 at 05'.

Take a surface breath and drop...problem solved.